P omer Bay is the most indented part of Medulin Bay, located on the coast of the significant landscape of Upper Kamenjak. This unusually shallow area was created during the last Ice Age, 10 000 years ago. It is surrounded by the mainland on three sides, while on the side facing Medulin Bay there is an embankment. It was built by the hands of the local people to hold fish. It is permeable in two places, and tides are the main factor that determines the level of the sea water in the bay. Salinity may vary from brackish to hypersaline water, depending on the rain, evaporation, and the fresh sea water that comes in with sea currents and storms, flooding in the winter or during high tide. Extreme variations in temperature and salinity create such conditions on the surface that, when strong bora wind blows during the winter, it may completely freeze over.
From a biological point of view, Pomer Bay is an extremely important area. Besides being the perfect place for spawning of many fish species as well as for the growth of young fish, this type of habitat is extremely rare, even at the European level. Such habitats are typical of the Venetian Lagoon, and many species found in Pomer Bay are not characteristic of the Croatian part of the coast, but precisely of the Venetian Lagoon.
T he whole area has been included in the Natura 2000 network. Since it is extremely shallow, with large variations in temperature, salinity and volume, and physically separated from the rest of the sea, it is classified as a coastal lagoon. Among the many animal and plant species, we should point out the meadows of seagrass (Cymodocea nodosa). The area is home to a large number of crabs, and there are also sea cucumbers, sea urchins, bristle worms, sponges, various stingers, and one particular kind of fish, Aphanius, which has been present on earth since the time of the Tethys Sea.
One other fact contributes to the significance of this area - in this extremely shallow area there are species that inhabit different types of habitat (muddy bottom, sandy bottom, rocky bottom) and species that prefer different depths of the sea.
. In addition to being below sea level and having a rich underwater life, this area is very important for many bird species that here find refuge and rest on their migratory path.
D ue to their terrain configuration, coastal lagoons are rare habitats on the eastern coast of the Adriatic. Like most low coastlines, this habitat is threatened by urbanisation and reclamation as well as pollution with solid or liquid waste. Therefore, all interventions in the vicinity of these threatened habitats must be specifically supervised and their physical, chemical and biological parameters need to be monitored in order to timely determine the negative changes.